1. Field of the Invention
In general, this patent application relates to video-recording devices and more particularly, but not by way of limitation, to systems that include split-screen video displays for use with law-enforcement vehicles.
2. History of the Related Art
Cameras and other video-recording devices have long been used to capture still images and video. In general, cameras include an enclosed hollow portion with an opening or aperture at one end to allow light to enter and a recording surface for capturing the light at another end. In addition, cameras often have a lens positioned in front of the aperture along an optical axis to gather incoming light and focus all or part of an image onto the recording surface.
Use of dashboard cameras in police vehicles has been known for years and is an integral part of a police department's evidence-gathering capability. One limitation of conventional cameras is a limited field of vision. Fields of view vary from camera to camera but, in general, most cameras have a field of view that ranges from a few degrees to, at most, 180°.
To overcome the limited field of view, surveillance cameras used for monitoring large areas are oftentimes mounted to mechanisms adapted to enable the camera to pan, tilt, and zoom in order to move objects into the camera's field of view. One type of camera, called an omnidirectional camera, has been used to monitor large areas without a need for mechanisms to enable pan, tilt, and zoom.
Some omnidirectional cameras may be adapted to capture images from all directions (i.e., a full sphere). However, many omnidirectional cameras do not capture a full sphere of images, but rather capture 360 degrees of images along a single axis with the field of view being limited angularly above and below the axis. As referred to herein, an omnidirectional camera is a camera adapted to capture omnidirectional images. The omnidirectional camera is adapted to capture wide-angle images from a wide-angle field of view up to and including 360-degree images from a 360-degree field of view. An omnidirectional image may be a wide-angle image, for example, of 130-190° from a wide-angle field of view, for example, of 130-360°. In some cases, the omnidirectional camera may have a field of view ranging from on the order of 180°, 190°, 200°, 210°, 220°, 230°, 240°, 250°, 260°, 270°, 280°, 290°, 300°, 310°, 320°, 330°, 340°, 350°, or 360° and the omnidirectional images may be less than or equal to a omnidirectional-camera field of view.
More recently, dual-lens devices have been developed that combine a narrow-view lens and an omnidirectional lens. These dual-lens devices typically allow recording of up to 360 degrees of images at a plurality of different resolutions. However, display of the output from such dual-lens devices in a way that eliminates unimportant portions of images remains problematic.